Martin Kilbinger, an astronomer (cosmologist) with whom we had worked on population Monte Carlo for cosmological inference [during the ANR-05-BLAN-0283- 04 ANR ECOSSTAT grant], has made the PMC C codes available on the CosmoPMC webpage. He has also written a CosmoPMC manual that is now available from arXiv. And he very kindly associated me to this publication, even though I never directly contributed to the codes… On a wider perspective, this collaboration between cosmologists and Bayesian and computational statisticians was both fruitful and enjoyable and I hope we can pursue it in the future. A very nice thing about astronomers (among many!) is that they naturally adopt a Bayesian way of thinking about their parameters. This, plus their high math and programming skills, makes the cost of entering a collaboration very low!